The present invention relates to the finding that TL1A enhances differentiation of TH17 cells, and enhance IL17 secretion from TH17 cells. In one embodiment, the present invention provides a method of treating an inflammatory disease comprising determining the presence of a TL1A signaling profile, and treating the disease by administering a composition comprising a therapeutically effective dosage of one or more inhibitors of TL1A or TH17 cell differentiation. In another embodiment, the disease is characterized by TH17 differentiation.
